Pemetaan Ground Acceleration Menggunakan Metode Probabilistic Seismic Hazard Analysis Di Propinsi Nusa Tenggara BaratPada Zona Megathrust.

Abstract

This study aims to map disaster-prone areas o f earthquake disaster in NTB Province using PSHA method to obtain a peak ground acceleration probability map periodically based on the latest earthquake data in megathrust zone and background zone as one o f earthquake disaster mitigation efforts. This research is based on earthquake occurrence data in NTB Province and surrounding area fo r 116 years which processed using software Ez-Frisk 7.52. The framework using the PSHA method starts from the phase o f collecting the earthquake data fo r 116 years at coordinates o f -6.33 ° LS to -11.33 ° LS and 112.45 ° east to 119.83 ° east obtained from the USGS, ISC and ANSS earthquake catalogs . Next, convert the magnitude into the magnitude scale o f the moment before the earthquake identification using Gardner and Knopoof criteria to obtain the a-b parameter. The determination o f attenuation function based on earthquake source modeling is determined by the researcher, ie the source o f earthquake interface subduction (megathrust) earthquake and the source o f earthquake intraslab subduction (deep background). The calculation o f peak ground acceleration values uses the basic probability theory developed by Cornell. The result o f spectral acceleration due to the source o f subduction earthquake in West Nusa Tenggara Province based on probabilistic analysis ranges from 0.04 g - 0.1 g fo r the re-period o f 500 years, while for the 2500 year re? period is 0.08 g - 0.3 g. For shallow background the earthquake ranges from 0.1 g - 0.3 g for the re-period o f500 years, while fo r the 2500 year re-period is 0.2g - 0.5g. While fo r the source o f deep background earthquakes ranged from 0.2 g - 0.3 g fo r the re-period o f500 years, while fo r the 2500 year re-period is 0.3 g - 0.4g. Keywords: